Tips

Avoid short and common words

This is the most likely cause of an unexpected failed search.
If your search terms include a common "stop word" (such as "the", "one", "your", "more", "right", "while", "when", "who", "which",
"such", "every", "about", "onto"), then your search will fail without any
results. Short numbers, and words that appear in half of all pages, will also not be found.
In this case, drop those words and rerun the search.

See Help:Common words, searching for which is not possible for the stop words filtered out by the database. From there one can at least go to a page with a stop word as title. Searching for the combination of one or more words and the common word "not" give a database query syntax error due to a bug in the software.

Search is case-insensitive

The searches for "fortran", "Fortran" and "FORTRAN" all return the same results.

Words with special characters

In a search for a word with a diaeresis, such as Sint Odiliënberg, it depends whether this ë is stored as one character or as "&euml;". In the first case one can simply search for Odilienberg (or Odiliënberg); in the second case it can only be found by searching for Odili, euml and/or nberg. This is actually a bug that should be fixed -- the entities should be folded into their raw character equivalents so all searches on them are equivalent. See also Help:Special characters.

Phrase

Search for a phrase by enclosing it in double quotation marks.

Wildcard

You can use a wildcard *, at the end of a search term only. To search for pages with the words "boat" or "boats" search like this: "boat*". You cannot use "*boat" to find Riverboat, etc.

Searching limitations and Gotchas

No regular expressions

Words in single quotes

If a word appears in a page with single quotes, you can only find it if you search for the word with quotes. Since this is rarely desirable it is better to use double quotes in pages, for which this problem does not arise.

An apostrophe is identical to a single quote, therefore Mu'ammar can be found searching for exactly that (and not otherwise). A word with apostrophe s is an exception in that it can be found also searching for the word without the apostrophe and the s.

Delay in updating the search index

For reasons of efficiency and priority, very recent changes to pages are not always immediately taken into account in searches.

Search options

Namespaces searched

The search only applies to the namespaces selected in the preferences. To search the other namespaces check or uncheck the tickboxes in "Search in namespaces" box found at the bottom of a search results page. Depending on the browser, a box may still be checked from a previous search, but may no longer be effective. To be sure the box is in effect, uncheck and recheck it.

Searching the image namespace means searching the image descriptions, i.e. the first parts of the image pages. For searching the titles, use Special:Imagelist.

Searching in single namespaces can also be achieved by typing the namespace, a colon, then the search term in the search box. For example, typing "Talk:Foo" will give all pages containing "foo" in the talk namespace.

To search the Help pages use //meta.wikimedia.org/wiki/Special:Search?ns12=1&fulltext=Search&search=x and replace the x in the URL by the search term. Replacing it in the search box does not work the same: the search is then in the namespaces specified in the preferences, instead of just in the help namespace.

Highlighting

Some portions of matching pages that contain the searched-for terms are shown, with the terms highlighted in red. You can set the number of lines extracted and the amount of text per line shown in your preferences.

If you search e.g. for "book" you get only pages with that word, not pages with "books" only. However, on pages with "book" and "books", also the part "book" of the word "books" is highlighted.

Other possibilities

list of all pages

Go button

Search field

Pressing the [Enter] key while the search field is active is equivalent to clicking on the [Go] button. While this is obvious when using Internet Explorer (tested on version 6), Mozilla (version 1.6 at least) provides no such indication.